The York County lawyer representing Garrett Cheney, 23, of South Berwick said in post-trial motions that a bystander implored jurors not to let Cheney “get away with it” and become another “Casey Anthony” as they were leaving the courthouse during a lunch break on July 26.

“The pressure this comment placed upon the jury cannot be credibly discounted and it deprived [the] defendant of his right to have his case decided by an impartial jury, one that remained untouched by prejudicial and improper outside influences,” defense attorney William Bly of Biddeford argued in seeking a trial for his client.

The motions for acquittal and-or a new trial were filed on Aug. 9. A hearing has been scheduled for Sept. 27 at the Penobscot Judicial Center before Superior Court Justice William Anderson, who presided at Cheney’s trial.

Penobscot County District Attorney R. Christopher Almy on Tuesday called Bly’s motions perfunctory.

“I expect that the court will deny them without much argument or even thought,” he said in a telephone interview. “These are fairly routine motions that are rarely granted. And there is no reason for them to be granted in this case.”

The judge was made aware of the bystander’s statement and jurors were questioned individually about it when they returned from lunch, Almy said.

“Mr. Bly at that time never raised any objection to continuing the trial and the judge found no reason to stop the trial of declare a mistrial,” the district attorney said. “There is no basis for his motion. It was all explored when it happened. The jurors were questioned and all agreed, even Mr. Bly, that there was no reason for a mistrial.”

Almy said that no one had been charged with jury tampering in the connection with the comments made to jurors.

“That issue of jury tampering was explored at the same time,” he said. “Based on what we have for evidence, there was no need go in that direction. … There was a thorough review of the whole incident.”

Bly also asked Anderson to vacate the jury’s verdict and acquit Cheney of all charges because the evidence presented was not sufficient to prove the defendant was guilty beyond a reasonable doubt.

“The lack of sufficient evidence to support the jury’s conviction in this case is further compounded by the fact that the jury clearly did not consider the evidence with appropriate care and diligence,” Bly said in the motion. “The trial in this matter stretched out over nearly two full weeks, involved testimony from eight different expert witnesses, several of whom had competing opinions regarding proof of causation and numerous other lay witnesses and law enforcement officers.

“Despite the length of the trial and extensive evidence presented to it over the course of the the trial, this jury deliberated for only two and half hours. It did not request a review of any testimony; it did not review key pieces of physical evidence. Instead, it returned a guilty verdict after very little deliberation and with minimal consideration of the facts before it.”

Almy called the verdict “totally justified.”

Cheney was in Orono on Jan. 29, 2010, visiting a cousin to celebrate the cousin’s 21st birthday, a witness told the jury last month.

After hitting Bakley, Cheney headed south on Interstate 95. His Chevrolet Silverado went off the highway about 3:30 a.m. Jan. 30 in Etna, according to testimony. The damaged pickup was towed to the storage lot of a Newport towing firm.

Cheney was not injured but was charged with drunken driving. His blood alcohol level was 0.15 percent, nearly twice the legal limit, two hours after his truck left I-95, according to previous testimony.

Bly conceded in his opening statement that his client was too drunk to drive and guilty of operating under the influence.

Cheney, who had no criminal history, faces up to 30 years in prison and a $50,000 fine on the manslaughter conviction, the most serious of the charges. Almy said after the trial that he would recommend a significant sentence be imposed.

A sentencing date is not expected to be set until after the hearing on Bly’s motion. The defense attorney said after the trial that he would eventually appeal Cheney’s conviction to the Maine Supreme Judicial Court.